The United States is one of only three countries in the world that remain uncommitted to the metric system. Perhaps to policymakers the decision to hang on to miles, pounds, and gallons is one of tradition. However, as a physics teacher I have seen firsthand how growing up with U.S. Customary Units (commonly called by the pseudonym "British…

Plans are under way to redefine the International System of Units (SI) around 2018. The new SI specifies the values of certain physical constants to define units. This article explains the new SI in order to provide a resource for high school teachers as well as for advanced students already familiar with the pre-2018 SI.

Since much of SI is based on physics and mathematics, physics teachers have the background to teach SI. We present this review and summary in a series of SI notes in order to help teachers answer many questions about the SI that often are, or should be, asked (for example, in workshops for teachers). SI should not be considered a jargon to set…

Using the triple beam balance to measure mass in metrics is just one of the many skills teachers want their students to master. The author has found a few effective and fun approaches to develop this skill over a couple of interesting days. With each activity, students are actively involved in the construction of knowledge: What is mass and how is…

Constructing model hot air balloons is an activity that captures the imaginations of students, enabling teachers to present required content to minds that are open to receive it. Additionally, there are few activities that lend themselves to integrating so much content across subject areas. In this article, the authors describe how they have…

Looks at what the problems are in the use of quantities and units in chemistry and what has been achieved until this time. Considers quantity and amount of substance, quotients of physical quantities, composition of mixed phases, and equations with quantities. Makes recommendations for future considerations. (CW)

This article provides a science lesson for the middle school level, the metric system is used for all methods of measurement. The example lesson utilizes edible fruit as the real-world focus and offers ideas for additional lessons and the integration of disciplines beyond mathematics. This lesson requires students to handle, examine, and possibly…

Discusses advantages of using the joule as the focus of a teaching strategy to unify the concept of energy. Includes applications to various energy forms and use of the joule in converting constants. A set of worked problems, using relationships discussed in the article, are available from the author. (JM)

Provides an overview and description of the metric system. Discusses the evolution of measurement systems and their early cultures, the beginnings of metric measurement, the history of measurement systems in the United States, the International System of Units, its general style and usage, and supplementary units. (RT)